1. Field of the Invention
The present invention relates to motion capture apparatus and method for recognizing a posture or a motion of an objective person in accordance with an image captured with a camera, and a motion capture program for use therein.
2. Description of the Related Art
It is necessary to realization of a natural interface between a human being and an apparatus to generally analyze information on various actions and voices of an operator, including a manual gesture and a body gesture of a human being, and to detect and recognize existence, intention, and the like of the human being. In order to attain this, the various techniques relating to analysis about a motion and an action of the human being have been investigated in the past. A motion analyzing technique can be roughly classified into a technique for acquiring motion information by using special markers or the like, and a technique for analyzing a motion based on an image analysis not using any of the markers.
A magnetic system, a mechanical system, an optical system, or the like is known as a system using special markers or the like. However, an optical motion capture system is especially frequently utilised as a recent motion tracking/capturing system. Motion capturing/analyzing systems such as an MX camera system (trademark) manufactured by Vicon Peaks Inc., an OptiTrack (trademark) manufactured by Natural Point Inc., and a Hawk Digital System (trademark) manufactured by Motion Analysis Corporation, have already been utilized in the fields of the Computer Graphics (CG), the movie production, and the like. The motion analysing system with markers has such a merit that information on a motion of a person can be previously measured. For this reason, the motion analyzing system with markers is frequently utilized in the fields such as the CG and the movie production for which the highly precise motion analysis is necessary.
However, in this system, a large-scale system configuration is necessary, and attachment of the markers to a human being imposes a burden on the human body. Therefore, it may not be possible to call this system a natural human machine interface (HMI).
Thus, the inventors of the present invention adopt the motion analyzing technique based on the image analysis not using any of the markers in order to realize the natural HMI in the general environment. Several motion analysing techniques each being based on the image analysis not using any of the markers have been investigated. Typically, there is given a motion and posture tracking technique based on a three-dimensional model of a person and a stereo image (for example, D. Demirdjian, T. Ko, T. Darrell, Constraining Human Body Tracking, Proceedings of the International Conference on Computer vision, 2003, hereinafter referred to as Non-patent Document 1). There is also given a person motion tracking technique based on a three-dimensional model of a person using a multiple cameras (for example, K. M. Cheung, S. Baker, J. K. Hodgins, and T. Konade, Markerless Human motion Transfer, Proceedings of the 2nd International Symposium on 3D Data Processing Visualization and Transmission, September, 2004, hereinafter referred to as Non-patent Document 2). There is also given a motion analyzing technique based on a person region and a movement model (for example, Ramanan, D., Forsyth, D A, Zisserman, A. “Strike a Pose: Tracking People by Finding Stylized Poses”, Computer Vision and Pattern Recognition (CVPR), San Diego, Calif., Jun. 2005, hereinafter referred to as Non-patent Document 3).